This invention relates to an insulated one-piece roof over heatable rooms, consisting of at least three layers, namely a solid or other load-bearing system, an insulating board and prepared roofing.
In one known roof, a bitumen-coated concrete ceiling is covered by a levelling layer to which a vapor sealing layer is applied. The actual insulating layer is then applied which is covered with a single-layer plastics sheet and then a three-layer bitumen felt. Following the application of another protective layer, the roof structure is weighted with gravel or receives a reflecting layer, for example of chippings or slate and the like.
The roof construction often used in practice is extremely complicated and hence troublesome. If the vapor sealing layer is not satisfactorily laid or if it is subsequently damaged (for example by settlement) water vapor penetrates through to the prepared roofing resulting in bulges and ultimately tearing of the roofing or, in the event of condensation, soaking of the construction. Another disadvantage is that the loose plastic sheeting (for example PVC), which must be laid in combination with a barrier layer due to plasticizer migration, must be weighted with pebbles to prevent them from being dislodged by wind. Apart from the additional gravelling required, this adds to the cost of the concrete ceiling which must be made thicker because of the increased weight thereon.
The object of the present invention is to provide an insulated one-piece roof which may readily be made from prefabricated sections, which does not require any additional ballast to prevent it from lifting, which is impervious to surface water and, despite the absence of vapor sealing layer underneath, does not have any tendency towards bubble formation in the prepared roofing caused by the diffusion of water vapor.